// SPDX-FileCopyrightText: 2023-2025 Sangfor Technologies Inc.
// SPDX-License-Identifier: Mulan PSL v2
package handler

import (
	"bytes"
	"fmt"
	"io/ioutil"
	"net"
	"net/http"
	"os"
	"runtime"
	"strings"

	"github.com/gin-gonic/gin"

	"code.geniusai.org/notebook-manager/pkg/entity"
	"code.geniusai.org/notebook-manager/pkg/log"
)

// stack returns a nicely formatted stack frame, skipping skip frames.
func stack(skip int) []byte {
	buf := new(bytes.Buffer) // the returned data
	// As we loop, we open files and read them. These variables record the currently
	// loaded file.
	var lines [][]byte
	var lastFile string
	for i := skip; ; i++ { // Skip the expected number of frames
		pc, file, line, ok := runtime.Caller(i)
		if !ok {
			break
		}
		// Print this much at least.  If we can't find the source, it won't show.
		fmt.Fprintf(buf, "%s:%d (0x%x)\n", file, line, pc)
		if file != lastFile {
			data, err := ioutil.ReadFile(file)
			if err != nil {
				continue
			}
			lines = bytes.Split(data, []byte{'\n'})
			lastFile = file
		}
		fmt.Fprintf(buf, "\t%s: %s\n", function(pc), source(lines, line))
	}
	return buf.Bytes()
}

// function returns, if possible, the name of the function containing the PC.
func function(pc uintptr) []byte {
	fn := runtime.FuncForPC(pc)
	if fn == nil {
		return []byte("???")
	}
	name := []byte(fn.Name())
	// The name includes the path name to the package, which is unnecessary
	// since the file name is already included.  Plus, it has center dots.
	// That is, we see
	//	runtime/debug.*T·ptrmethod
	// and want
	//	*T.ptrmethod
	// Also the package path might contains dot (e.g. code.google.com/...),
	// so first eliminate the path prefix
	if lastSlash := bytes.LastIndex(name, []byte("/")); lastSlash >= 0 {
		name = name[lastSlash+1:]
	}
	if period := bytes.Index(name, []byte(".")); period >= 0 {
		name = name[period+1:]
	}
	name = bytes.Replace(name, []byte("·"), []byte("."), -1)
	return name
}

// source returns a space-trimmed slice of the n'th line.
func source(lines [][]byte, n int) []byte {
	n-- // in stack trace, lines are 1-indexed but our array is 0-indexed
	if n < 0 || n >= len(lines) {
		return []byte("???")
	}
	return bytes.TrimSpace(lines[n])
}

// panic的处理
func RecoveryInterceptor(c *gin.Context) {
	defer func() {
		if p := recover(); p != nil {
			// Check for a broken connection, as it is not really a
			// condition that warrants a panic stack trace.
			var brokenPipe bool
			if ne, ok := p.(*net.OpError); ok {
				if se, ok := ne.Err.(*os.SyscallError); ok {
					if strings.Contains(strings.ToLower(se.Error()), "broken pipe") || strings.Contains(strings.ToLower(se.Error()), "connection reset by peer") {
						brokenPipe = true
					}
				}
			}
			stack := stack(3)
			log.Errorf("panic error: %v \n%s", p, stack)
			if !brokenPipe {
				c.JSON(http.StatusOK, gin.H{
					"code":    entity.NotebookErrorModule + entity.CodeSystemError,
					"msg":     entity.MsgSystemError,
					"success": false,
					"data":    gin.H{},
				})
			} else {
				c.Abort()
			}
		}
	}()
	c.Next()
}
